A study published this week in the Journal of Sleep Research focused on the impact of "weekend sleeping" — or, simply, sleeping on days off — and concluded that a little extra snoozing on days off can possibly make up for lost sleep on the weekdays.

The study, led by Torbjörn Åkerstedt, the director of the Stress Research Institute at Stockholm University, tracked more than 43,000 people over a span of 13 years.

The study found that individuals younger than 65 who slept for fewer than 5 hours per night the entire week faced a 52% higher mortality rate. However, individuals who slept for fewer than the recommended 7 hours per night on weekdays, but slept for an extra hour or two on weekends, lived just as long as folks who sleep 7 hours a night the whole week.

"The mortality rate among participants with short sleep during weekdays, but long sleep during weekends, did not differ from the rate of the reference group," the study summary says. "Among individuals ≥65 years old, no association between weekend sleep or weekday/weekend sleep durations and mortality was observed. In conclusion, short, but not long, weekend sleep was associated with an increased mortality in subjects <65 years. In the same age group, short sleep (or long sleep) on both weekdays and weekend showed increased mortality. Possibly, long weekend sleep may compensate for short weekday sleep."

So there you have it.

All that said, however, that doesn't mean you should start depriving yourself of sleep during the work week. From The Washington Post:

Epidemiologists who spoke with The Washington Post described the result as a plausible finding, if not a statistically robust one, that deserves more investigation.

Michael Grandner, director of the Sleep and Health Research Program at the University of Arizona's College of Medicine, who was not involved with this work, warned that sleep is not like a financial transaction. We can't deposit zzzs over the weekend and expect to cash them out later.

A superior metaphor, he said, is a diet. For the sleep-deprived, sleeping in on a weekend is like eating a salad after a series of hamburger dinners — healthier, sure, but from “one perspective the damage is done.”